1. Field
The present invention generally relates to surge protectors and more particularly relates to DC pass or DC short RF coaxial surge protectors with non-linear protection devices.
2. Background
Communications equipment, computers, home stereo amplifiers, televisions, and other electronic devices are increasingly manufactured using small electronic components which are very vulnerable to damage from electrical energy surges. Surge variations in power and transmission line voltages, as well as noise, can change the operating range of the equipment and can severely damage and/or destroy electronic devices. Moreover, these electronic devices can be very expensive to repair and replace. Therefore, a cost effective way to protect these components from power surges is needed.
There are many sources which can cause harmful electrical energy surges. One source is radio frequency (RF) interference that can be coupled to power and transmission lines from a multitude of sources. The power and transmission lines act as large antennas that may extend over several miles, thereby collecting a significant amount of RF noise power from such sources as radio broadcast antennas. Another source of the harmful RF energy is from the equipment to be protected itself, such as computers. Older computers may emit significant amounts of RF interference. Another harmful source is conductive noise, which is generated by equipment connected to the power and transmission lines and which is conducted along the power lines to the equipment to be protected. Still another source of harmful electrical energy is lightning. Lightning is a complex electromagnetic energy source having potentials estimated from 5 million to 20 million volts and currents reaching thousands of amperes.
Ideally, what is desired in a DC pass or DC short RF surge suppression device is having a compact size, a low insertion loss, and a low voltage standing wave ratio (VSWR) that can protect hardware equipment from harmful electrical energy emitted from the above described sources.